Fitting for conduits for electrical conductors.



A. W. SCLATER,

FITTING FOR CONDUITS FOR ELECTRICAL CONDUCTORS.

APPLICATION EILED DEC 17, 19H.

1,246,333. Patented Nov. 13, 1917.

1 2% 3 Mar.

UNITED STATES PATENT OFFICE.

ABTHUB WILLIAM SCLATER, 0F WESTMINSTEB, LONDON, ENGLAND.

FITTING FOR CONDUITS FOR ELECTRICAL GONDUC'I'ORS.

Specification of Letters Patent.

PatentedNov. 13, 1917;

To all whom it may concern:

Be it known that I, ARTHUR WILLIAM SCLATER, a subject of the King of England, residing at 14 Sackville street, Piccadilly, in the city of Westminster, London, England, have invented certain new and useful Improvements in Fittings for Conduits for Electrical Conductors, of which the followin is a specification.

his invention relates to fittings for conduits for electrical conductors and refers to an improved construction of such devices,

by the use of which the conduits can be easily fixed in position, more cheaply and expeditiously than is the case with the fittings at present in use.

Metal conduits for electrical conductors, when erected, should be electrically and mechanically continuous throughout.

The conduit generally employed consists of lengths of metallic tubing, with screwed ends, which engage with internally screwed connectors, sockets, boxes or other fittings, thus forming a continuous electrical and mechanical system.

According to my invention I do away with all screwed tubes, screwed sockets and other screwed fittings and pinchin screws, and also with all eccentric boring o sockets, projections, segmental cam surfaces and other intricate contours, and I connect the tube forming the conduit to the outlet of the box socket or other fitting of metal hereinafter called the outlet, in the following manner The interior of the outlet is slightly elliptical in form and into this outlet I place a hollow metal connecting piece, the outer surface of which is also slightly elliptical in form, which connecting piece slides easily into the outlet, the major axes of the two ellipses coinciding.

The inner surface of the connecting piece is circular in form and is of such size as to fit tightly the outside of the tube forming the conduit, which is pushed into it, the tube, the connecting piece and the outlet being all concentric.

The connectin piece is provided with an enlarged end, 0 hexagonalor other shape with which a wrench or spanner can enga e. The socket box or other fitting isheld y, and the connecting piece is turned asfar as possible in either direction.

The efiect of turning the connecting piece is that the major axis of such piece is forced as far as it will go toward the minor axis of the outlet, and in being so forced the interior of the connecting piece is distorted with the result that the tube forming the conduit inside it, is gripped very tightly and at the same time the exterior surface of the connecting piece is tightly wedged against the interior surface'of the outlet.

In some cases it is advisable to form a longitudinal saw cut or slit in the connecting piece so as to permit the interior bore of such piece being reduced in size so as to grip the tube forming the conduit.

In order that my invention may be clearly understood, I will now proceed to describe the same with reference to the accompanying drawings in which Figure 1 represents a side elevation of a socket and two connecting pieces, forming a coupling by means of which two tubes are connected.

Fig. 2 represents an end elevation of the same coupling.

Fig. 3 represents the same coupling in 1ongitudinal section.

F1g. 8 is a longitu inal section illustrating a modified form of connecting piece hereinafter more fully described.

' The same letters of reference are employed to denote the same parts in all the views: a is the socket, by means of which the tubes 6 b forming the conduit are coupled togethersee Figs. 1 to 4. The interior of the socket outlets is slightly elliptical in form, the major axis on c d being greater than the minor axis on e f.

Into each outlet 0 of the socket is slipped a connecting piece g, the exterior surface of which is slightly elliptical, the major axis on c (1 being greater than theminor axis on e f the connecting piece 9 may have a longi- I v forced toward the minor axis of the socket.

As' a result the inner surface of the connecting piece 9 is distorted or reduced, the longitudinal slit or saw cut h, where such 1s provided closing up and the tube belng tightly gripped by the inside of the connecting piece 9, while at the same time the outer\ surface of the connecting piece is ti htly wedged against the inner surface 0 the socket. Thus in addition to a strong mechanical joint, good electrical continuity 1s made between the tubes 6 b forming the conduit.

It will be readily understood that half of I a socket such as'a can form theoutlet of a box'or other fitting to which a conduit 6 has to be connected.

An arrangement of this description 1s shown at Figs. 5 to 7. D

In these figures a a are the outlets of the box which outlets are formed in the same manner as the socket in Figs. 1 to 4. b b arethe tubes forming the conduit. The inner surface of the outlets a a is slightly elliptical in form, the major axis on c d being greater than the minor axis on e f, g is a connecting piece, the outer surface of whlch is slightly elliptical the major axis a 01 being greater than the minor axis a f. The connecting piece 9 is formed with a hexagonal head 3', and the longitudinal saw cut or sllt It is also preferably provided therein.

In fittmg the parts in position the tube forming the conduit 72. is inserted into the connecting piece 9 which, in turn is inserted into the outlet a. On turning the connecting piece 9 by means of the hexagonal head 7', the major axis on c d is moved toward the position 0 (1 the connecting piece 9 being thereby compressed on the line 0 d and the interior bore being reduced, the tube is tightly gripped and at the same time the outer surface of the connecting piece 9 is wedged against the interior of the surface of the outlet a, thus forming a strong mechanical, as well as a good electrical joint.

In practice it is desirable to eliminate all sharp ledges or projections in the conduit and in order to efi'ect this it is advisable to form the outlet with a step or shoulder la as shown in Fig. 5 against which the tube forming the conduit b and the connecting piece 9, butt, the inner surface of the tube coming flush with the inner edge of the shoulder or, as an alternative the connection illustrated at Fig. 8 may be adopted. In this case the connecting piece 9 is provided at the inner end with an inwardly projecting step or flange m against which the inner end of the tube b butts, the inner edge of the said flange or step being flush with the interior of the tube 6. The other side of the flange or step m is .rounded or beveled off so that no sharp projection is present.

The particular details of the fitting may be varied within the scope of the appended claims.

What I claim and desire to secure by Letters Patent of the United States of Amer- 1ca 1s 1. A connecting fitting for conduits for electrical conductors, comprising in combination an outlet formed with an elliptical interior, a connecting piece having a corresponding but slightly smaller elliptical exterior adapted to fit into the elliptical .interior of the outlet, such connecting piece having a circular interior, adapted to fit closely the outside of the conduit tube to be connected the elliptical interior of the outlet, the elliptical exterior of the connecting piece and the circular interior of the sai nation an outlet formed with an ellipticalinterior, a connecting piece having a corresponding but slightly smaller elliptical exterior adapted to fit into the elliptical interior of the outlet, such connectin piece beingprovided with a longitudinal sit and having a circular interior, adapted to fit closely the outside of the conduit tube to be connected the elliptical interior of the outlet, the elliptical exterior of the connecting piece and the circular interior of the said connecting piece all having a common center and means for enabling the connecting piece to be rotated about its axis for the purposes set forth.

3. A'connecting fitting for conduits for electrical conductors, comprising in combination an outlet formed with an elliptical interlor, a connecting piece having a corresponding but slightly smaller elliptical exterior adapted to fit into the elliptical interior of the outlet, such connecting piece being provided with a longitudinal slit and having a circular interior adapted to fit closely the outside of the conduit tube to be connected the elliptical interior of the outelectrical conductors comprising in combination, an outlet formed with an elliptical interior, a connecting piece having a corresponding but slightly smaller elliptical exterior adapted to fit into the elliptical interior of the outlet, such connectlng piece being provided with a longitudinal slit and having a circular interior adapted to fit closely the outside of the conduit tube to be connected, an inwardly projecting flange at the inner end of such connecting piece, such flange forming a step against which the inner end of the conduit is adapted to butt having its inner edge flush with the interior of the conduit when the latter is in position and being rounded ofi' on the other side, the elliptical interior of theoutlet, the elliptical exterior of the connecting piece and the circular interior of the said connecting piece all having a comnfon center, and means at the end of the said connecting piece for enabling such piece to be rotated about its axis all substantially as and for the purposes described.

In testimony whereof I aflix my signature in presence of two Witnesses.

ARTHUR WILLIAM SOLATER. Witnesses:

A. C. VIDAL, A. W. LEE. 

